JOURNAL OF ALLOYS AND COMPOUNDS
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2017
·
IF 3.133
Xin Wang,Xiaotao Yuan,Xiangye Liu,Wujie Dong,Chenlong Dong,Minghe Lou,Juncen Li,Tianquan Lin,Fuqiang Huang
Nitrogen-doped black TiO 2 (N x :TiO 2−x ) recently attracted attention as a novel photocatalyst . It has higher electrical conductivity and more suitable energy level for oxygen reduction and hydrogen evolution than pure TiO 2 due to the presence of Ti 3+ species. The unique electronic structure and strong metal-support interaction make it a candidate support for Pt-based electrocatalyst . Carbon is universal as support of Pt-based electrocatalyst. However, it is restricted to the poor durability and bad methanol tolerance. On the contrary, the chemical stability of nitrogen-doped TiO 2 contributes to the higher durability and methanol tolerance of Pt/N x :TiO 2−x than Pt/C catalyst. Monodisperse Pt nanoparticles are loaded on N x :TiO 2−x by a facile borohydride reduction method. The Pt/N x :TiO 2−x hybrid shows better oxygen reduction reaction (ORR) activity with the half wave potential of 0.78 V ( vs. reversible hydrogen electrode) than Pt and good hydrogen evolution reaction (HER) performance with 19 mV onset overpotential, similar to Pt/C catalyst. More importantly, Pt/N x :TiO 2−x catalyst has robust durability and higher methanol tolerance than Pt/C catalyst. All these electrostatic performances stem from the suitable energy level for ORR and HER and the strong interaction between Pt and N x :TiO 2−x support. This hybrid material is a promising candidate for the fuel cell in the future.
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高影响因子
Polymers
·
2017
·Vol. 9
·期 7
·301
·
IF 3.364
Xiaoyan Tu,Chao Meng,Zhe Liu,Lu Sun,Xianshuo Zhang,Mingkui Zhang,Mingrui Sun,Liwei Ma,Mingzhu Liu,Hua Wei
Polymers with advanced topological architectures are promising materials for wide applications due to their structure-generated unique properties different from that of the linear analogues. The elegant integration of stimuli-responsive polymers with such advanced architectures can create novel materials with virtues from both moieties, are thus a hot subject of research for both fundamental and practical investigations. To fabricate cyclic brush polymer-based intelligent materials for biomedical applications, herein, we designed and synthesized thermo-sensitive cyclic brush polymers with poly(N-isopropylacrylamide) (PNIPAAm) brushes by controlled living radical polymerization using cyclic multimacroinitiator. The thermo-induced phase transition behaviors of the resultant cyclic brush polymers with different compositions were investigated in detail by temperature-dependent optical transmittance measurements, and compared with the properties of bottlebrush and linear counterparts. Interestingly, the cloud point transition temperature (Tcp) of cyclic brush PNIPAAm could be regulated by the chain length of PNIPAAm brush. Although the bottlebrush polymers with the same composition exhibited similarly structurally dependentTcps behaviors to the cyclic brush polymers, the cyclic brush PNIPAAm did show higher critical aggregation concentration (CAC) and enhanced stability against dilution than the bottlebrush counterpart. The readily tailorableTcps together with the ability to form highly stable nanoparticles makes thermo-sensitive cyclic brush PNIPAAm a promising candidate for controlled drug delivery.Keywords:cyclic brush polymer;thermo-sensitivity;poly(N-isopropylacrylamide)
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高影响因子
CARBON
·
2017
·
IF 6.337
Jingyan Liu,Yang Liu,Peng Li,Luhai Wang,Haoran Zhang,Hui Liu,Jialiang Liu,Yixian Wang,Wei Tian,Xiaobo Wang,Zhongtao Li,Mingbo Wu
Fe-N-doped porous carbon derived from petroleum asphalt (NPCA) was prepared via a facile template synthesis method, with urea as nitrogen source while α-Fe 2 O 3 nanoparticles as template and Fe source. The as-prepared NPCA calcined at 900 °C (NPCA-900) exhibits excellent electrocatalytic performance with high diffusion-limiting current density and stability comparable to those of commercial Pt/C catalysts in alkaline environment . The remarkable ORR performance of NPCA could be ascribed to the abundant porosity, large specific surface area (1060 m 2 g −1 ), as well as the doping of Fe-N (especially pyridinic N). The NPCA derived from cheap petroleum asphalt has good application future in the field of catalysis, while it may pave a new way to realize the clean and high value utilization of heavy oils.
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高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2016
·
IF 3.926
Yiman Zhao,Yajing Chen,Zhichao Xiong,Xudong Sun,Quanqing Zhang,Yangyang Gan,Lingyi Zhang,Weibing Zhang
In consideration of the close connection between glycopeptides and human diseases, the efficient method to separate and enrich glycopeptides from complex biological samples is urgently required. In the work, we developed a magnetic zwitterionic-hydrophilic material for highly effective separation and analysis of glycopeptides from complex samples. The Fe 3 O 4 particles were covered with a thick layer of polymer by one-step reflux-precipitation polymerization (RPP), subsequently decorated by Au nanoparticles (Au NPs) through in situ reduction and finally modified with zwitterionic groups. The abundant zwitterionic sites facilitate the selective enrichment of glycopeptides. Besides, the prepared Fe 3 O 4 @PGMA@Au- l -cys showed high detection sensitivity (5 fmol IgG digest), approving enrichment capacity (75 mg g −1 ), satisfactory enrichment recovery (89.8%), and great performance in the analysis and profiling of low-abundance N-linked glycopeptides. Furthermore, the prepared material was employed in the enrichment of glycopeptides in intricate biological samples, and 774 unique N -glycosylation sites from 411 N -glycosylated proteins were reliably identified in three replicate analyses of a 75 μg protein sample extracted from mouse liver, suggesting wide application prospect in glycoproteomics.
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高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
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2016
·
IF 1.733
Xi Wang,Qian Xiang,Weiwei Cao,Feng Jin,Xuefeng Peng,Bingcheng Hu,Xiaodong Xing
Magnetic recyclable bactericidal nanocomposites (Fe3O4@PDMC) were well-designed and prepared by coating of Fe3O4 nanoparticles with quaternarized N-halamine polymers via the free radical polymerization process. In which, 5,5-dimethylhydantoinyl-(3-ethyl-methacrylamine)propyl dimethylammonium bromide (DEMPA), a new monomeric N-halamine precursor, was used as a coating material as well as the dual-functional bactericidal agent. The developed Fe3O4@PDMC nanocomposites exhibited suitable size and super-paramagnetic responsibility. The antibacterial results showed that the Fe3O4@PDMC nanocomposites had excellent biocidal abilities against Staphylococcus aureus (gram-positive) and Escherichia coli (gram-negative). Furthermore, the TTC (Triphenyl Tetrazolium Chloride)–dehydrogenase activity assay confirmed that the reductions of the bacteria were mainly attributed to powerful biocidal effects of the coating polymer instead of bacteria capture by the cationic surface. Interestingly, due to the magnetic responsive performance of Fe3O4, the as-prepared Fe3O4@PDMC nanocomposites can be recycled by a magnet and reused for antibacterium through the quenching/rechlorination procedure. All the results presented in this study show that the proposed Fe3O4@PDMC nanocomposites could be a competitive candidate for water purification systems and household sanitation.
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高影响因子
RSC Advances
·
2015
·Vol. 5
·期 76
·62024-62032
·
IF 3.84
Qian Feng,Dongyan Tang,Haitao Lv,Weile Zhang,Wenbo Li
Well fabricated ZnO nanorods (ZnO NRs) arrays with preferred-orientation that grown on pre-deposited ZnO seed layers substrate were selected to graft thermo-responsive polymers of poly(N-isopropylacrylamide) (PNIPAM) by surface-initiated atom transfer radical polymerization (SI-ATRP). As a controlled/“living” radical polymerization, SI-ATRP could endow the systems with the characteristics of the grafted PNIPAM, meanwhile, with the maintaining of the properties of the ZnO NRs. The structures of ZnO and the grafted polymer with the relatively high molecular weights (Mn, 24 300) and narrow molecular weight distributions (Mw/Mn, 1.19) that determined by GPC detection, were characterized by XRD and FT-IR. The graft amount of PNIPAM on ZnO NRs and the interactions between the two components were determined by TG and XPS, respectively. The relatively thin layers of PNIPAM (∼15 nm) formed around NRs via SI-ATRP method were observed by SEM. And the temperature-sensitivity of the grafted nanorods were proved by contact angles measurements. Furthermore, photodegradation of Rhodamine B (Rh-B) by the grafted nanorods revealed that ZnO NRs–PNIPAM exhibited photocatalysis and temperature responsibility characteristics, indicating the significant potential applications with tunable responsiveness by changing the environmental conditions.
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ChemSusChem
·
2015
·Vol. 8
·期 15
·2487-2491
·
IF 7.657
Qun Li,Wei Cui,Jingqi Tian,Zhicai Xing,Qian Liu,Wei Xing,Abdullah M. Asiri,Xuping Sun
Graphical Who WON the race? N-Doped carbon-coated tungsten oxynitride nanowire arrays on carbon cloth (WON@NC NAs/CC) are prepared by annealing the WO 3 NAs/CC precursor under an Ar atmosphere in the presence of dicyandiamide and are used as a 3 D hydrogen evolution cathode with superior activity and stability over the pH 0–14 range. PBS=phosphate-buffered saline, RHE=reversible hydrogen electrode. It is highly desired but still challenging to develop active nonprecious metal hydrogen evolution reaction (HER) electrocatalysts operating under all pH conditions. Herein, the development of three-dimensional N-doped carbon-coated tungsten oxynitride nanowire arrays on carbon cloth as a highly efficient and durable HER cathode was explored. The material delivers current densities of 10 and 100 mA cm −2 at overpotentials of 106 and 172 mV, respectively, in acidic medium, and it also performs well in neutral and basic electrolytes.
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高影响因子
MONATSHEFTE FUR CHEMIE
·
2014
·Vol. 145
·期 12
·1925-1931
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IF 1.347
Tu Xingzhao,Zhou Lihong,Li Zhijie,Lei Ning,Zeng Qingle
Abstract The carbon-heteroatom bond formation is an important research field. Transition-metal-free synthesis of medicinally important heterocycles avoids products of transition metal contamination, and thus it is an environmentally friendly and cost-saving process. A transition-metal-free domino C-S/C-N formation for the synthesis of imidazobenzothiazines from 2-mercaptobenzimidazoles and 2-halobenzyl bromides is developed. The desired products were obtained in good to excellent yields. The mechanism of domino nucleophilic substitution (S N 2) and nucleophilic aromatic substitution (S N Ar) is proposed. Graphical abstract
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高影响因子
Nano Research
·
2014
·Vol. 7
·期 12
·1809-1819
·
IF 6.963
Han Chuanlong,Wang Shiping,Wang Jing,Li Mingming,Deng Jiang,Li Haoran,Wang Yong
Encompassing ecological and economic concerns, the utilization of biomass to produce carbonaceous materials has attracted intensive research and industrial interest. Using nitrogen containing precursors could realize an in situ and homogeneous incorporation of nitrogen into the carbonaceous materials with a controlled process. Herein, N-doped hollow core-disordered mesoporous shell carbonaceous nanospheres (HCDMSs) were synthesized from glucosamine hydrochloride (GAH), an applicable carbohydrate-based derivative. The obtained HCDMSs possessed controlled size (∼450-50 nm) and shell thickness (∼70-10 nm), suitable nitrogen contents (∼6.7-4.4 wt.%), and Brunauer-Emmett-Teller (BET) surface areas up to 770 m 2 ·g −1 . These materials show excellent electrocatalytic activity as a metal-free catalyst for the oxygen reduction reaction (ORR) in both alkaline and acidic media. Specifically, the prepared HCDMS-1 exhibits a high diffusion-limited current, and superior durability and better immunity towards methanol crossover and CO poisoning for ORR in alkaline solution than a commercial 20 wt.% Pt/C catalyst.
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POLYMERS FOR ADVANCED TECHNOLOGIES
·
2014
·Vol. 25
·期 6
·684-688
·
IF 1.964
Chang Peng,Wu Pan,Lin Bao,Shu Chen,Yi Chen,Mingsong Han,Yuanqin Xiong,Weijian Xu
We report a facile method that combined sol–gel reaction, reversible addition–fragmentation chain transfer (RAFT)/macromolecular design via interchange of the xanthates process and thiol-ene click reaction to prepare monodisperse silica core-poly( N -vinylimidazole) (PVim) shell microspheres of 200 nm in average diameters. First, silica with C = C double bonds was prepared by the sol–gel reaction of 3-(trimethoxysilyl)propyl methacrylates (MPS) with tetraethoxysilane in ethanol; SiO 2 @PVim were subsequently prepared by grafting PVim chain (Mn = 9800 g/mol, polydispersity index = 1.22) to MPS-SiO 2 via the thiol-ene click chemisty. The obtained SiO 2 @PVim microspheres show higher catalytic activity toward the hydrolysis of p -nitrophenyl acetate compared with the PVim homopolymers. The as-prepared composites have been characterized by scanning electron microscopy, transmission electron microscopy, thermal gravimetric analysis and Fourier transform infrared spectrometry analysis. Copyright © 2014 John Wiley & Sons, Ltd.
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Nano Energy
·
2013
·
IF 0
Yan-Qing Zhang,De-Kun Ma,Yan-Ge Zhang,Wei Chen,Shao-Ming Huang
N-doped nanostructured carbon materials have attracted much attention because the doping can induce new unique physical and chemical properties of carbon. In this study, we report, for the first time, that N-doped carbon quantum dots (NCQDs) can combine with rutile TiO 2 and form NCQDs/TiO 2 hierarchical microspheres assembled by nanorods with enhanced photocatalytic activities under visible light irradiation. As a result, the pseudo-first-order reaction constant for the degradation of rhodamine B (RhB) on NCQDs/TiO 2 (0.11 min −1 ) is 215.7, 7.3 and 1.3 times much larger than that of NCQDs (0.00051 min −1 ), TiO 2 (0.015 min −1 ), and CQDs/TiO 2 (0.086 min −1 ), respectively. The functions of NCQDs were discussed and a new synergistic photosensitized mechanism was proposed for the degradation of RhB on the as-synthesized NCQDs/TiO 2 nanocomposites based on the experimental results. NCQDs were also applied as metal-free sensitizers in dye-sensitized solar cells (DSSCs) for the first time. A preliminary study shows that under one sun illumination (AM 1.5), the open circuit voltage and fill factor values reach 0.46 V and 43%, respectively, achieving a power conversion efficiency of 0.13% in the proof-of-concept TiO 2 -based DSSCs device. The performance of NCQDs sensitized solar cells surpasses that of N-free counterpart as well. N-doping lowered the work function of CQDs, which was responsible for enhanced photocatalytic activity of NCQDs/TiO 2 and better NCQDs sensitized TiO 2 -based solar cell performance.
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Artificial Cells Nanomedicine and Biotechnology
·
2014
·
IF 0
Meihao Liang,Xiaoliang Zheng,Linglan Tu,Zhen Ma,Zunyuan Wang,Dongmei Yan,Zhengrong Shen
In order to study the liver targeting of the N-galactosylated chitosan (GC) polymer in liver, we first conjugated the lactobionic acid with chitosan (CS) to obtain the carrier of GC with different degree of substitution of lactosyl group. Western blot was performed to detect the expression levels of the asialoglycoprotein receptors (ASGPR) in the cell lines of HepG2, SMMC-7721, and HL-7702. The protein level of ASGPR was lower in HepG2 compared to HL-7702 and SMMC-7721. Although all treated by CS, viabilities of HL-7702 and HepG2 did not experience any significant drop, while viability of SMMC-7721 decreased 15% on average from control. It was the first data about the inhibitory effect of GC on the liver cells. Fluorescein isothiocyanate (FITC) labeled GC (GC-FITC) was injected intravenously into mice at a dose of 0.02 μmol/mouse. GC-FITC showed maximum liver localization at 5 min and even detectable at 48 h after injection. Further, the accumulation of GC in liver was about 5.4-fold higher than that of CS. In conclusion, GC demonstrated its higher efficacy in drug liver targeting and thus could be a more promising drug or gene carrier in future therapies.
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